Lady Ambrosia was a child kidnapper and member of The Blacklist.
Lady Ambrosia, whose real name is never revealed, and her husband, Noah Shuster, once had 2 sons together, one of whom, Theo, was mentally handicapped. When the boys were in a canoe accident that resulted in the death of the other son, Lady Ambrosia snapped. Using her husband's job at an adoption agency to find children whose parents were going to give them up because of their disabilities, such as autism or muteness, she kidnapped them with Theo's help and made them part of a cult she started, telling the victims they would be "turned into butterflies" and live forever as children. In order to keep them from having to face adulthood as outcasts, she would kill them when they reached the age of 12, the end of adolesence, by having Theo gas them to death with nitrous oxide and then wrap them into a cocoon of burlap and wooden sticks and throw it into a well on the cult's compound, an abandoned schoolhouse known within the cult as The Colony.
- Ambrosia is a reference to Greek mythology.